Recently I've stumbled upon an impressive collection of video walkthroughs for all levels of
Rise of the Triad (shareware episode and
Extreme Rise of the Triad included, plus a few extras):
http://www.youtube.com/user/Psychede.../0/gpqPBku8YvQ
All videos are supplied with interesting and witty comments, listening to which makes a great entertainment in itself, apart from the walkthroughs that are rather detailed and in most cases cover all of the secret areas within a particular level. These videos are probably the number one source of in-depth information about the game alongside with the
official FAQ. Apparently, the guy who did these videos is a prominent member of
Something Awful.
As an undeniable confirmation of quality of this video collection, Joe Siegler himself gave it
his delighted approval.
Another thing definitely worth watching too is this video review of the game, which is part of the Era Game Reviews (a pretty nice series of reviews of old games, by the way):
http://www.youtube.com/watch?v=b4JEx2XQ-_Q